Systemic lupus erythematosus (SLE) is an autoimmune disorder of unknown etiology characterized by diverse T cell effector dysfunction. Interleukin-2 (IL-2) production is decreased in patients with SLE and lupus-prone mice and this contributes to the immunopathogenesis of the disease. This proposal is based on published and preliminary data which demonstrate that anti-CD3/TCR antibodies present in the sera of patients with SLE cause translocation of Calcium/calmodulin kinase 4 (CaMK4) from the cytoplasm to the nucleus where it suppresses IL-2 production. In the lupus prone MRL.lpr lupus-prone mouse, pharmacologic inhibition or genetic deletion of CaMK4 with a small drug inhibitor suppresses autoimmunity, mesangial cell proliferation and lupus nephritis. In additional data, CaMK4 appears to be involved in the generation of regulatory T cells. Based on these data we hypothesize that the ser/thr kinase CaMK4 contributes to the expression of autoimmunity by suppressing IL-2 production and Treg function and to the development of lupus nephritis by promoting mesangial cell proliferation. First, we will establish that CaMK4 translocates to the nucleus of SLE T cells, determine how it becomes activated and how it affects immunoregulation. Second, we will establish whether CaMK4 expressed in mesangial cells is independently responsible for excessive proliferation and the development of lupus nephritis. And, third, we plan to use nanolipogels loaded with an inhibitor of CaMK4 and tagged with antibodies to deliver the drug to T and mesangial cells. To carry out the studies we will use cells from patients with SLE and a newly constructed MRL.lpr mouse which lacks CaMK4 and nanolipogel technology to delver the CaMK4 inhibitor. The proposal identifies a new Ser/Thr kinase, CaMK4, in the regulation/dysregulation of the immune response and proliferation of mesangial cells and proposes the use of a novel nanolipogel delivery system to target a small drug inhibitor of CaMK4 to T and mesangial cells. The significance of the proposed work lies with the fact that it presents a novel target for the treatment of SLE and that it develops a targeted delivery of a small drug.